This invention relates to an interior automotive trim member, having improved scratch resistance and, more particularly, to an automotive instrument panel having improved scratch resistance.
Instrument panels for automobiles, and other interior automotive trim members, typically comprise a hard backing substrate, a soft layer of elastomeric material disposed over and bonded to the backing substrate and a soft polymeric skin which is disposed over and bonded to the layer of elastomeric material.
The backing substrate is typically made of a relatively rigid material such as a hard polymeric material or metal. The layer of elastomeric material is relatively soft and preferably has a hardness which is less than the hardness of the skin or the backing substrate.
Polyvinylchloride (PVC) based instrument panels have been widely used. These PVC-based instrument panels typically comprise a hard polymeric backing substrate, a soft polyurethane (PU) foam layer bonded to the backing substrate and a soft PVC skin bonded to the polyurethane foam layer. A coating is usually applied onto the PVC skin for gloss control as well as for lowering the potential of mar and/or scratch damage. This type of instrument panel having a PVC-PU and polymeric backing substrate composite is not environmentally friendly. Recycling of the composite is difficult and sometimes impossible due to the byproducts formed during thermal treatment. Moreover, incineration of the composite is virtually unacceptable because the byproducts are corrosive and toxic.
Another type of instrument panel which has been commonly used comprises a soft polyolefin skin, a polyolefin foam such as polypropylene foam, and a polyolefin backing substrate. As each of the components of the instrument panel are made of polyolefin, recycling and other environmental considerations of the instrument panel are advantageous. However, coatings must be applied to the skin for gloss and scratch resistance control. Typically, in applying the coating, adhesion promoter must be applied in between the coating and the polyolefin soft skin.
The necessity of these coatings adds considerable expense and time to the manufacture of these prior art instrument panels.
It would be desirable to provide an instrument panel which can be easily and more cost effectively manufactured relative to the prior art instrument panels.
It would be further desirable to provide an instrument panel which is scratch resistant and has suitable gloss control without the use of a coating over the soft skin.
It would also be further desirable to provide an instrument panel which can be easily recycled.
The present invention relates to an interior automotive trim member which comprises a backing substrate, a layer of elastomeric material bonded to and overlying the backing substrate, and a soft skin formed of polyolefinic material. The soft skin is bonded to and overlies the layer of elastomeric material. The soft skin is cured by electron beam curing.
The electron beam curing (treating) of the soft skin results in the soft skin having a scratch resistant surface, thus eliminating the need for a coating on the soft skin. The gloss of the soft skin can be controlled by adding filler to the polyolefinic material. Moreover, the electron beam curing of the polyolefinic material takes place without the addition of any cross-linking catalyst/accelerator to the polyolefinic material.
The present invention also relates to a method of making a soft skin for use with an interior automotive trim member comprising a backing substrate, a layer of elastomeric material overlying and bonded to the backing substrate, and the soft skin overlying and bonded to the layer of elastomeric material. The method comprises providing a polyolefinic material, and exposing the polyolefinic material to electron beam radiation to cure the polyolefinic material.
In one embodiment, the layer of elastomeric material comprises polyolefin foam comprising a curable mixture of a polyolefinic material and a foaming agent. The polyolefinic material of the soft skin and the polyolefin foam of the polyolefinic material of the layer of elastomeric material are exposed to the electron beam radiation simultaneously such that both the polyolefinic material of the soft skin and the polyolefin foam of the layer of elastomeric material cure simultaneously.
In another embodiment, the polyolefinic material of the soft skin is exposed to the electron beam radiation prior to being bonded to the layer of elastomeric material.
In another embodiment, the backing substrate and the layer of elastomeric material also comprise a polyolefinic material to allow for relatively easy recycling of the trim member.